{"product_id":"2-56-unc-phillips-flat-head-countersunk-machine-screws-carbon-steel","title":"2-56 UNC Phillips Flat Head Countersunk Machine Screws, 1\/4\" — Carbon Steel, Bright Nickel","description":"\u003cscript type=\"application\/ld+json\"\u003e\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What does 2-56 UNC mean on a machine screw?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"2-56 UNC refers to the Unified National Coarse thread standard. The \\\"2\\\" indicates the screw diameter (\\\"#2\\\", approximately 0.086 inches or 2.18mm), and \\\"56\\\" means 56 threads per inch. UNC is the most common coarse thread series used in the United States for general-purpose fastening.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Is 1\/4 inch the right length for my application?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A 1\/4\\\" (6.35mm) screw is typically suitable for fastening materials that are 1\/8\\\" to 3\/16\\\" thick, leaving adequate thread engagement in the mating material. For countersunk applications, account for the depth of the countersink so the head sits flush. If your material is thicker, a longer #2-56 screw may be needed.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"What Phillips bit size do I need for a #2-56 screw?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"A #2-56 machine screw typically uses a PH0 (Phillips #0) or PH1 (Phillips #1) driver bit, depending on the specific head size. Always test-fit the bit before applying torque. Using an oversized bit on a small screw head can strip the drive recess, especially in softer carbon steel.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Are these screws compatible with standard #2-56 nuts and tapped holes?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Yes. These screws use the standard 2-56 UNC thread (56 threads per inch), which is compatible with standard #2-56 UNC nuts, threaded inserts, and tapped holes. They are not compatible with metric M2 threads, which have a different pitch and diameter.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How corrosion-resistant is bright nickel plating on carbon steel screws?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Bright nickel plating provides a decorative, shiny finish and moderate corrosion resistance for indoor use. It is generally suitable for dry or low-humidity environments such as electronics enclosures, hobby models, and indoor fixtures. For outdoor, marine, or high-humidity applications, stainless steel fasteners are generally a better choice.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"How strong are #2-56 carbon steel machine screws?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Carbon steel #2-56 machine screws are generally rated to SAE Grade 2 or equivalent, with a tensile strength typically in the range of 60,000–74,000 psi (approximately 415–510 MPa). For small-diameter screws like #2, the actual load capacity is limited by the minor thread cross-section. These screws are suitable for light-duty fastening in electronics, models, and precision instruments, not for structural or high-load applications.\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Should I choose carbon steel or stainless steel for #2-56 countersunk screws?\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Carbon steel with bright nickel plating (this product) is a good choice for indoor applications where a shiny, decorative finish is desired and corrosion is not a primary concern. Stainless steel is generally preferred for outdoor, humid, or corrosive environments. For most electronics, RC, and hobby applications in dry conditions, carbon steel bright nickel is typically sufficient.\"\n      }\n    }\n  ]\n}\n\u003c\/script\u003e\n\n\u003cdiv class=\"hdiy-desc\"\u003e\n\n  \u003cdiv class=\"hdiy-overview\"\u003e\n    \u003ch2\u003e2-56 UNC Phillips Flat Head Countersunk Machine Screws — Bright Nickel Carbon Steel for Electronics, Models \u0026amp; Precision Builds\u003c\/h2\u003e\n    \u003cp\u003eWhen you need small-diameter inch-standard fasteners that sit flush with the surface and won’t strip under a precision screwdriver, the options at most hardware stores fall short. Electronics assemblers, RC hobbyists, model builders, and instrument technicians who work with #2-56 UNC hardware regularly know how hard it is to find 2-56 UNC Phillips countersunk machine screws in bulk quantities with a clean, consistent finish. These 1\/4\" carbon steel bright nickel flat head screws are stocked in packs from 100 to 500 pieces, ready for production runs or workshop replenishment.\u003c\/p\u003e\n    \u003cp\u003eEach pack contains 2-56 UNC Phillips flat head (countersunk) machine screws in carbon steel with a bright nickel finish. Thread size is #2-56 UNC (approximately 0.086\" \/ 2.18mm diameter, 56 threads per inch). Length is 1\/4\" (6.35mm \/ ≈6.4mm). The flat countersunk head profile allows the screw to sit flush with or below the mating surface. Packs are available in 100, 200, 300, 400, or 500 pieces.\u003c\/p\u003e\n    \u003cp\u003eTypical use cases include electronics enclosure assembly where #2-56 flat head screws are used to mount PCBs, panels, or covers flush without protruding heads; RC car and drone chassis builds where small UNC countersunk screws secure body panels and battery trays; and precision instrument repair and model making where the bright nickel finish provides a clean, reflective appearance on visible fastener locations.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-compat\"\u003e\n    \u003cspan class=\"hdiy-compat-icon\"\u003eℹ️\u003c\/span\u003e\n    \u003cstrong\u003eCompatibility:\u003c\/strong\u003e 2-56 UNC thread standard (56 TPI) — fits standard #2-56 UNC tapped holes, threaded inserts, and nuts. \u003cstrong\u003eNot compatible with metric M2 threads.\u003c\/strong\u003e Countersunk head angle is typically 82° (UNC standard) — verify your countersink angle before ordering.\n  \u003c\/div\u003e\n\n  \u003ch2\u003e✅ Key Features of These 2-56 UNC Phillips Countersunk Machine Screws\u003c\/h2\u003e\n  \u003cul class=\"hdiy-features\"\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔩\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eFlush-Mount Flat Head Profile\u003c\/strong\u003e — The countersunk head sits flush with or below the mating surface, eliminating snag points on panels, enclosures, and chassis where protruding fastener heads are not acceptable in electronics or model builds.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e✨\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eBright Nickel Finish\u003c\/strong\u003e — The electroplated bright nickel coating provides a shiny, decorative appearance and moderate corrosion resistance for indoor use — well-suited for visible fastener locations in precision instruments, hobby models, and electronics enclosures.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🇺🇸\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eUNC Inch-Standard Thread\u003c\/strong\u003e — 2-56 UNC (56 threads per inch) is the standard thread for #2 machine screws in the United States, ensuring direct compatibility with existing #2-56 tapped holes, threaded inserts, and nuts without adapters or re-tapping.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📦\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eBulk Packs Up to 500 Pieces\u003c\/strong\u003e — Available in 100, 200, 300, 400, or 500-piece packs, making these #2-56 countersunk screws practical for production assembly, workshop stock, and repair kits without the cost premium of small retail packaging.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e🔧\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003ePhillips Drive for Wide Tool Compatibility\u003c\/strong\u003e — The Phillips (cross) drive recess works with standard PH0 and PH1 screwdrivers and bits, which are universally available in electronics toolkits, making these screws easy to install in field repairs and bench assembly alike.\u003c\/span\u003e\n\u003c\/li\u003e\n    \u003cli\u003e\n\u003cspan class=\"hdiy-icon\"\u003e📏\u003c\/span\u003e\u003cspan\u003e\u003cstrong\u003eConsistent 1\/4\" Length Across All Pack Sizes\u003c\/strong\u003e — A single, well-defined length (1\/4\" \/ 6.35mm) simplifies inventory management and BOM sourcing for engineers and hobbyists who standardize on one screw specification across a product or build.\u003c\/span\u003e\n\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch2\u003e📐 Technical Specifications — 2-56 UNC Phillips Flat Head Countersunk Machine Screws\u003c\/h2\u003e\n  \u003cdiv class=\"hdiy-table-wrap\"\u003e\n    \u003ctable\u003e\n      \u003ctbody\u003e\n        \u003ctr\u003e\n\u003cth\u003eThread Standard\u003c\/th\u003e\n\u003ctd\u003e2-56 UNC (Unified National Coarse, 56 threads per inch)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eNominal Diameter\u003c\/th\u003e\n\u003ctd\u003e#2 — approximately 0.086\" (2.18mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eLength\u003c\/th\u003e\n\u003ctd\u003e1\/4\" (6.35mm)\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eHead Style\u003c\/th\u003e\n\u003ctd\u003eFlat Head (Countersunk), Phillips Drive\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eDrive Type\u003c\/th\u003e\n\u003ctd\u003ePhillips — typically PH0 or PH1\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eCountersink Angle\u003c\/th\u003e\n\u003ctd\u003eTypically 82° (UNC standard) — contact us to confirm\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eMaterial\u003c\/th\u003e\n\u003ctd\u003eCarbon Steel\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eFinish\u003c\/th\u003e\n\u003ctd\u003eBright Nickel Electroplating\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eCorrosion Resistance\u003c\/th\u003e\n\u003ctd\u003eModerate — suitable for indoor \/ dry environments\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eTensile Strength\u003c\/th\u003e\n\u003ctd\u003eTypically 60,000–74,000 psi (approx. 415–510 MPa) — contact us to confirm exact grade\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003ePack Quantities\u003c\/th\u003e\n\u003ctd\u003e100 \/ 200 \/ 300 \/ 400 \/ 500 pieces — see variant options\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003ctr\u003e\n\u003cth\u003eCountry of Origin\u003c\/th\u003e\n\u003ctd\u003eContact us to confirm\u003c\/td\u003e\n\u003c\/tr\u003e\n      \u003c\/tbody\u003e\n    \u003c\/table\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-note\"\u003e\n    \u003cspan class=\"hdiy-note-icon\"\u003e⚠️\u003c\/span\u003e\n    \u003cstrong\u003eNote:\u003c\/strong\u003e 2-56 UNC and metric M2 threads are \u003cstrong\u003enot interchangeable\u003c\/strong\u003e. Verify your existing hardware uses #2-56 UNC before ordering. The countersink angle for UNC flat head screws is typically 82° — confirm your countersink matches before installation.\n  \u003c\/div\u003e\n\n  \u003ch2\u003e❓ Frequently Asked Questions\u003c\/h2\u003e\n  \u003cdiv class=\"hdiy-faq\"\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat does 2-56 UNC mean on a machine screw?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003e2-56 UNC refers to the Unified National Coarse thread standard. The “2” indicates the screw diameter (“#2”, approximately 0.086\" or 2.18mm), and “56” means 56 threads per inch. UNC is the most common coarse thread series used in the United States for general-purpose fastening. It is the standard thread for #2 machine screws in American-made electronics, instruments, and equipment.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eIs 1\/4\" the right length for my application?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eA 1\/4\" (6.35mm) screw is typically suitable for fastening materials that are 1\/8\" to 3\/16\" thick, leaving adequate thread engagement in the mating material or nut. For countersunk applications, account for the depth of the countersink so the head sits flush with the surface. If your material is thicker than about 3\/16\", a longer #2-56 screw may be needed to achieve sufficient thread engagement.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eWhat Phillips bit size do I need for a #2-56 screw?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eA #2-56 machine screw typically uses a PH0 (Phillips #0) or PH1 (Phillips #1) driver bit, depending on the specific head size. Always test-fit the bit before applying torque — a loose-fitting bit will cam out and damage the drive recess. Using a precision screwdriver with a well-fitting PH0 bit is generally recommended for small screws like #2-56 to avoid stripping.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eAre these screws compatible with standard #2-56 nuts and tapped holes?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eYes. These screws use the standard 2-56 UNC thread (56 threads per inch), which is compatible with standard #2-56 UNC nuts, threaded inserts, and tapped holes. They are \u003cstrong\u003enot\u003c\/strong\u003e compatible with metric M2 threads, which have a different pitch (0.4mm) and a slightly different nominal diameter. If you are unsure which thread your existing hardware uses, check with a thread gauge before ordering.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow corrosion-resistant is bright nickel plating on carbon steel screws?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eBright nickel plating provides a decorative, shiny finish and moderate corrosion resistance for indoor use. It is generally suitable for dry or low-humidity environments such as electronics enclosures, hobby models, and indoor fixtures. The nickel layer protects the underlying carbon steel from light oxidation and surface rust in normal indoor conditions. For outdoor, marine, or high-humidity applications, stainless steel fasteners are generally a better choice.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eHow strong are #2-56 carbon steel machine screws?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eCarbon steel #2-56 machine screws are generally rated to SAE Grade 2 or equivalent, with a tensile strength typically in the range of 60,000–74,000 psi (approximately 415–510 MPa). For small-diameter screws like #2, the actual load capacity is limited by the minor thread cross-section. These screws are suitable for light-duty fastening in electronics, models, and precision instruments — not for structural or high-load applications. Contact us to confirm the exact property class if your application has specific strength requirements.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n    \u003cdetails\u003e\n      \u003csummary\u003eShould I choose carbon steel or stainless steel for #2-56 countersunk screws?\u003c\/summary\u003e\n      \u003cdiv class=\"hdiy-faq-body\"\u003e\n        \u003cp\u003eCarbon steel with bright nickel plating (this product) is a good choice for indoor applications where a shiny, decorative finish is desired and corrosion is not a primary concern. Stainless steel is generally preferred for outdoor, humid, or corrosive environments. For most electronics, RC, and hobby applications in dry conditions, carbon steel bright nickel is typically sufficient and offers a cost advantage over stainless for bulk purchases.\u003c\/p\u003e\n      \u003c\/div\u003e\n    \u003c\/details\u003e\n\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"hdiy-cta\"\u003e\n    🛒 Select your quantity above, then add to cart — ships from our US warehouse.\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"HomeDIYer","offers":[{"title":"Carbon Steel \/ Bright Nickel \/ 2-56 X 1\/4\" \/ 100 PCS","offer_id":52285309583634,"sku":"GYJLTJLWJ04088x1","price":4.94,"currency_code":"USD","in_stock":true},{"title":"Carbon Steel \/ Bright Nickel \/ 2-56 X 1\/4\" \/ 200 PCS","offer_id":52285309616402,"sku":"GYJLTJLWJ04088x2","price":9.51,"currency_code":"USD","in_stock":true},{"title":"Carbon Steel \/ Bright Nickel \/ 2-56 X 1\/4\" \/ 300 PCS","offer_id":52285309649170,"sku":"GYJLTJLWJ04088x3","price":13.55,"currency_code":"USD","in_stock":true},{"title":"Carbon Steel \/ Bright Nickel \/ 2-56 X 1\/4\" \/ 400 PCS","offer_id":52285309681938,"sku":"GYJLTJLWJ04088x4","price":17.58,"currency_code":"USD","in_stock":true},{"title":"Carbon Steel \/ Bright Nickel \/ 2-56 X 1\/4\" \/ 500 PCS","offer_id":52285309714706,"sku":"GYJLTJLWJ04088x5","price":21.62,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0884\/8936\/1682\/files\/Picture1of3_9fd78426-8f7c-40b1-aecb-48790529a193.jpg?v=1780502947","url":"https:\/\/homediyer.com\/products\/2-56-unc-phillips-flat-head-countersunk-machine-screws-carbon-steel","provider":"HomeDIYer","version":"1.0","type":"link"}